Measuring turbine blades was once one of the most painful jobs in aerospace manufacturing.
Manual gauging for hours. Guesswork. One missed flaw that can destroy an entire aircraft engine. No wonder so many aerospace suppliers are turning their backs on old methods and embracing automated inspection systems that work quicker, smarter and with zero-error.
Here’s the thing…
Pressure is on like never before. One defective blade can destroy a jet engine. Worldwide, manufacturing defects cost companies an estimated $1 trillion annually due to dimensional errors and quality control failures. That’s a massive amount of money going up in flames every year.
Modern aerospace can’t afford that anymore.
Here’s what’s covered:
- What Is Turbine Blade Measurement?
- Why Manual Inspection Is Falling Behind
- How Automated Turbine Blade Inspection Works
- Why Aerospace Suppliers Are All In
What Is Turbine Blade Measurement?
Turbine blade gaging is the verification of size, geometry and surface finish of each individual blade prior to installation into a jet engine.
That includes:
- Airfoil profile and thickness
- Root and platform dimensions
- Cooling hole placement
- Coating thickness
- Surface defects like cracks or pores
Possibly the most challenging area of the blade to inspect is the root of the blade, also known as the fir tree. This is the area of the blade that keys into the engine disk and even a very small geometric error could lead to catastrophic blade failure due to extreme centrifugal load. Therefore, fir tree turbine blade inspection has evolved to be one of the most critical inspection points during the entire turbine blade measurement process.
Modern engines have hundreds of blades. Each individual blade has to be within microns of its design spec. Otherwise you lose engine performance… or worse case scenario, it catastrophically fails in-flight.
Pretty scary, right?
That’s exactly why suppliers are moving fast to automate the process.
Why Manual Inspection Is Falling Behind
Measuring turbine blades by hand was an industry practice for decades. Comparators, gauges and mechanical probes were utilized to manually inspect each blade against a template.
The problem?
It’s slow. It’s subjective. And it doesn’t scale.
Aerospace suppliers are feeling unprecedented pressure to produce more blades, faster than ever, while maintaining quality. Manual inspection methods are struggling to keep pace. Research has demonstrated humans miss defects repeatedly. Inspectors don’t agree on the same blade. Fatigue causes inspectors to miss cracks and pores. Complex shapes are extremely difficult to measure manually. Plus, documentation is messy and creates auditing nightmares.
Then there’s the cost issue.
Maintenance of propulsion systems accounts for a significant portion of aircraft operating costs. Airfoil-related operations such as blade inspection and blade replacement account for nearly 50% of engine module overhaul expenditures. Missed defects are exponentially amplified downstream.
The old methods just aren’t cutting it anymore.
How Automated Turbine Blade Inspection Works
Automatic turbine blade measuring machines combine various technologies to replace human inspection.
Primary assets are machine vision cameras, 3D optical scanners (including structured light and blue light scanners), computed tomography to detect internal defects, and Artificial Intelligence based defect detection software. These technologies combined allow collection of millions of data points across each blade in seconds.
They automatically compare each measurement to the CAD model and highlight any discrepancy, regardless of size.
Better still?
They never get fatigued. They never have an off day. And they never disagree with each other on if a blade measures up. Each blade is tested exactly the same way, every time.
Consistency at that level is transformative for aerospace suppliers that must validate every component meets specifications. Especially now that AI models are exceeding 90% accuracy rates in identifying blade defects, the discrepancy between human and machine inspection continues to grow.
Why Aerospace Suppliers Are All In
Why are Aerospace suppliers investing in automated inspection? Not because it’s cool new technology. They are investing because it addresses pain points that cannot be solved manually.
Here’s why the shift is happening now.
Speed
Robots can inspect blades in seconds, rather than minutes. Seconds add up when you have hundreds of blades going through your production line each day. Suppliers have more time to meet tighter deadlines without sacrificing quality.
Accuracy
Automated turbine blade measurement systems detect flaws invisible to the naked eye. Micro-cracks, small geometric anomalies and internal pores all easily escape human inspection.
Fewer defects missed translates to fewer defective blades reaching the assembly line. Which means there will be fewer catastrophic failures downstream.
Traceability
Every measurement is automatically logged and saved. That means if an issue crops up down the road, suppliers have an exhaustive digital paper trail of precisely what was measured, when and how. Big deal for aerospace quality audits and certification. It also allows you to easily identify trends and correct issues in your manufacturing process before they spiral out of control.
Cost Savings
Yes it costs money to purchase automated inspection systems. But ultimately they pay for themselves many times over. Fewer defective blades get through. Less rework. Less scrap. And engine manufacturers eliminate the astronomical price of a field failure… millions of dollars per event.
Buyer Demand
Large OEMs (Boeing, Airbus, GE Aerospace, Rolls-Royce, etc.) are demanding more data driven proof of quality from their suppliers. No more manual gauges and inspectors sign-off. Buyers want the complete digital measurement report for every blade… and only automated inspection can scale to meet that level of demand.
Buyers will refuse to do business with suppliers without automated inspection systems. You don’t want to be that supplier.
Safety
When it comes down to it, it’s all about safety. Jet engine turbine blades reach temperatures in excess of 1,600°C and experience centrifugal loads in excess of 10,000 x g. There is no margin for error. Automated turbine blade measurement allows suppliers to know with confidence that every blade shipped out of the factory will perform under those harsh conditions.
The Bottom Line
Turbine blade measurement is one of the most critical quality control steps in aerospace manufacturing. Get it right, and engines can safely run for thousands of hours. Get it wrong… Needless to say, the results can be disastrous.
Automated inspection systems are rapidly becoming the new standard and for good reason. Inspection automation is quicker, more precise and more reliable than previous manual techniques. By embracing this technology now, aerospace suppliers will be ensuring they:
- Deliver better quality blades
- Meet tighter production timelines
- Reduce scrap and rework costs
- Stay competitive in a demanding market
Things are changing. Automated turbine blade measurement is the new standard, and aerospace suppliers who fail to adapt will soon be left behind by those who have.